The present invention relates to a sterilizing method and apparatus for sterilizing or eliminating pathogens living in water. More particularly, the invention is concerned with a sterilizing method and apparatus that are capable of safely sterilizing or eliminating pathogenic protozoa having a shell and other bacteria.
At present, the disinfection of water by utility companies is performed using chlorine. For sterilizing purposes, however, disinfection using chlorine is ineffective against pathogenic protozoa having a shell such as, for example, cryptosporidium.
The use of powerful chemicals may be effective in enhancing the sterilizing effect. In this case, however, even if the sterilizing effect is attained, there arises the problem of environmental pollution. Thus, without careful consideration, the use of such chemicals must be avoided.
U.S. Pat. No. 5,611,993 describes a method of sterilizing a continuous flow of wastewater containing bacteria which includes applying high frequency sound waves to the continuous flow of wastewater to cause cavitation in the wastewater. However, to the best of the present inventors' knowledge, sterilizing pathogenic protozoa having a shell such as, for example, cryptosporidium is not known in the prior art.